This disclosure is related to removing water from quaternary ammonium salts.
Quaternary ammonium salts are used in a wide variety of reactions. Frequently quaternary ammonium salts are used as phase transfer catalysts. In some reactions the presence of water in the phase transfer catalyst decreases the amount of product produced by the reaction or, in some cases, prevents the reaction from occurring. While quaternary ammonium salts can be used in solid form, the solid form can contain water as many quaternary ammonium salts absorb water from the atmosphere. Straightforward methods of drying the quaternary ammonium salt solid such as heating in an oven can result in the formation of significant amounts of degradation products, which can then interfere with or negatively influence subsequent reactions. Additionally when the quaternary ammonium salt is used as a catalyst for commercial scale reactions it can be difficult to accurately add the solid material to the reaction vessel.
There remains a need in the art for drying quaternary ammonium salts, particularly dry quaternary ammonium salts that are substantially free of degradation products and are in a form suitable for use with commercial scale reactions.